Ginkgo is not only tenacious, but also known as the “living fossil”. The study found that the secret of Ginkgo’s longlife is mainly due to two reasons: first, the tree trunk formation layer stem cells do not enter the aging stage; Recently, Yangzhou University Ginkgo Research Team, Beijing Forestry University Lin Venus team and forest molecular design and breeding high-precision center cooperation, found that Ginkgo ancient tree longevity is not a single longevity gene regulation, but the growth and aging process of a combination of factors.
The findings were published online in the Proceedings of the National Academy of Sciences.
Ginkgo is not only tenacious, but also known as the “living fossil”, it has survived on Earth for hundreds of millions of years, so what is the reason why Ginkgo tree can live so long? Recently, the Science and Technology Daily reporter interviewed the relevant experts of the scientific research team.
After the mass extinction, the rise of quilt plants Ginkgo 270 million years to survive the survival of the present
Wang Li, a professor at Yangzhou University who has been studying Ginkgo for more than 20 years, told Science and Technology Daily that before the emergence of ginkgo and other naked plants, early maintenance plants such as shimatsu, wedge leaf, true ferns, seed ferns, kodas, and seed plants, such as the ancestors of the former naked plants, were mainly distributed on land. During the second period, the naked plants bred with seeds because of their greater adaptability, the breeding got rid of the water restrictions and began to flourish, gradually replacing the dominant position of ferns.
“Based on the fossil evidence found, early naked plants such as Ginkgo appeared on Earth at least 270 million years ago, but it is important to note that these early fossil species are close ancestorspeciess in the ginkgo, where the existing ginkgo is located, not the existing Ginkgo. Wang Li said.
About 252 million years ago, the Earth’s biosphere experienced a historical event called the “Dilandfill-Triassic Extinction.” Fossil records show that the vast majority of marine life disappeared from the holocaust, nearly half of the land animals were destroyed, and plants on the ground died.
140 million years ago, the new darling of nature, the quilt plant, suddenly appeared and began to devour the living space of the naked plant.
Yangzhou University Ginkgo research team introduced, naked plants are woody plants, long life cycle, slow growth, sexual reproduction is generally through wind-borne pollination, pollination efficiency is low. And the subplant growth is short, fast growth, pollination methods are diverse, most of the quilt plants generation short, in the same time period, cell chromosomal combination recombination, hybridization, genetic variation and other opportunities more, resulting in rapid species evolution.
In particular, a large number of quilt plants have evolved a co-evolution relationship with animals, such as providing nectar to pollinators, ripe fruits to attract birds to eat, etc., greatly improving the efficiency of selection evolution, so that quilt plant diversity outbreak, can quickly occupy a variety of habitat space, and can adapt to climate change more quickly.
Not only were quilted plants squeezed into living space, but the Cretaceous-Third Age extinction event, 65 million years ago, gave the naked plant a heavy blow. This extinction event not only caused the dinosaurgroup to die, but also nearly flattened the land of tall trees, unfortunately, naked plants are basically tall trees.
In this series of blows, Ginkgo became the only surviving species of Ginkgo Ginkgo. “Although the Ginkgo family flourished during the Jurassic and Cretaceous periods, fossils showed that there were a large number of Ginkgo near-edge species in the Ginkgo family at that time, the extinction of these close-edge species was clearly related to earth’s climate change and ice age through the Third and Fourth Ice Ages. Wang Li said the existing Ginkgo survived because some of its population sits in China’s uncapped Noah’s Ark region (Yunnan, Sichuan, Hubei and other places). “In fact, not only ginkgo, but also some naked plants such as water fir, silver fir, giant fir, etc. have survived. The reason soning is the survivor effect of local geographical location on the one hand, and on the other hand, it is related to the strong resistance and adaptability of these species. “
Stem cells are unfailing and resistant to strength, and are an important reason for Ginkgo’s “eternal youth”
Almost all multicellular organisms cannot escape aging and eventually lead to individual death. Aging in humans and animals is thought to be mainly related to telomere loss, DNA damage, DNA mutation accumulation, epigenetic changes and other factors, life expectancy is generally only a few decades, the longest is only 100 years. Unlike animals, however, some tree species in nature are still growing strongly for hundreds or even thousands of years, but their longevity mechanism has been unclear.
Yangzhou University Ginkgo research team, Beijing Forestry University Lin Venus team and forest molecular design and breeding high-precision center research found that Ginkgo longevity secret there are two reasons: First, the tree trunk formation layer stem cells do not enter the aging stage;
Many plants, such as many annual crops, begin to age once they have flowered, leading to individual death, which means that death is the default procedure pre-set in the individual growth and development of the species. Most multicellular organisms do this, just as when people reach old age, organ tissues will inevitably age. But the researchers found that ginkgo trees, more than 600 years old, and although stem cell division slowed, there was no sign of aging, and that all physiological and molecular indicators associated with aging were not significantly different from those of trees more than 20 years old. This continuous ability of stem cells to divide continuously is one of the important reasons for Ginkgo’s eternal youth.
At the same time, Ginkgo’s resistance to adversity, pests and germs R gene number is much more than other species, lignin monomer, flavonoids and ferncompound metabolic pathway gene number and expression in ginkgo ancient trees also did not decline, these metabolites with special protective function in the ancient tree cumulative effect, greatly enhanced the resistance of the tree. Yangzhou University Ginkgo research team believes that Ginkgo resistance genes, especially the ability to resist various extreme environments is very strong, which is the main reason for Ginkgo can survive a variety of extinction events. In addition, the continuous synthesis of lignin and other substances increasethed the density and strength of the trunk, supporting the growing tree body. This is like human, although into old age, but the immune capacity, skeletal muscle capacity is still very strong, thus greatly extending life.
“The study found that ginkgo ancient tree longevity is not a single longevity gene regulation, but the result of the comprehensive balance of many factors in the growth and aging process, which is of great scientific significance to reveal the mechanism of growth and aging regulation of trees at the individual level.” Wang Li said.
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Ginkgo “Longevity” thanks to human domestication
In fact, ginkgo’s long career has also encountered an existential crisis, fortunately they met human beings.
Ginkgo went extinct in North America about 5 million years ago; Ginkgo went extinct in Europe about 2.6 million years ago; and since 2.6 million years ago, the Earth has experienced several ice ages, and the number of ginkgo smaller than other endangered species is very rare.
It was not until later, after being domesticated by humans, that Ginkgo truly escaped extinction. Experts believe that Ginkgo can survive to the present and human domestication cultivation, there is a direct relationship.
It is precisely because of the Ginkgo resistance genes, vitality is tenacious, especially for human beings have a lot of value, so human sanse choose Ginkgo to domesticate cultivation. Ginkgo has ornamental value, its leaf-shaped strange, beautiful tree, is an important ornamental tree species, Ginkgo has edible, medicinal value, its seeds edible, Ginkgo biloba is also the main raw material for the treatment of cardiovascular disease drugs. At present, ginkgo is grown as an economic tree species in many areas.
Ginkgo is fortunate that the number of ginkgos in the world has increased rapidly through the introduction of human son. Ginkgo is now widely distributed and has become an important scenic tree species in different parts of the world in roads, parks and scenic spots.